JP2022026359A - Steel pipe joining structure in ground reinforcement method - Google Patents

Abstract

To provide a steel pipe joining structure, as a steel pipe joining structure for forming a pile-like ground reinforcement body by joining a plurality of steel pipes, which does not require welding work at a construction site, in which joining structure is simple and a work is easy to have excellent workability, and which can easily secure joining quality.SOLUTION: A steel pipe joining structure in a ground reinforcement method which makes a steel pipe penetrate underground by a rotary pressing-in method comprises: vertically long rod-like bodies 3 welded to be fixed to outer faces of upper and lower steel pipes 1 and 2 abutted on each other to be joined; a curved plate 4 having long holes 4a with a contour engaged with the upper and lower rod-like bodies and having a cross section along the pipe outer faces; upper and lower bolts 6 penetrating bolt insertion holes provided in upper and lower parts of the curved plate 4 and bolt insertion holes provided in the upper and lower steel pipes at the same position; and a nut 7 screwed with each bolt to be fastened. A feature of the ground reinforcement method that a property against a bending force and a tensile force (a pulling-out force) acting on a pile-like ground reinforcement body in an earthquake is not required is effectively utilized.SELECTED DRAWING: Figure 1

Description

The present invention relates to a steel pipe joining structure for joining steel pipes to each other in a ground reinforcement method in which the steel pipes are penetrated into the ground by a rotary press-fitting method when a plurality of steel pipes are joined to form a pile-shaped ground reinforcing body. ..

In the ground reinforcement method, when a plurality of steel pipes are joined to form a pile-shaped ground reinforcing body, generally, the upper steel pipe is welded to the lower steel pipe at the construction site.
However, it is becoming difficult to secure welding technicians at the construction site, and from the viewpoint of ensuring the quality of joints, a construction method that does not depend on human skill is required.
The following Patent Documents 1 to 4 are examples of the steel pipe joining structure when the steel pipe is penetrated into the ground by the rotary press-fitting method as the foundation method, but these steel pipe joining structures are also adopted in the ground reinforcement method. May be done.

For steel pipe piles, various methods for joining steel pipe piles that do not require welding have been proposed.
For example, in Patent Document 1, a male joint 24 having a thread is welded and fixed to one end 22 of each steel pipe main body 21 and a female joint 26 having a thread groove is welded and fixed to the other end. Therefore, at the construction site, the lower pile steel pipe and the upper pile steel pipe have a structure in which the male joint 24 and the female joint 26 hands are screwed and joined (the reference numeral is the reference numeral in Patent Document 1). board).

In Patent Document 2, steel pipe piles 1 and 1 adjacent to each other on the upper and lower sides are fitted and connected by a short joint pipe 2 fitted to the butt end portion, but one end side of the joint pipe 2 is lower by welding at a factory. It is joined to the steel pipe pile 1 on the side, and on the other end side of the joint pipe 2, the solidifying agent 13 is filled in the fitting gap 12 between the upper steel pipe pile 1 and the joint pipe 2, and both steel pipes are solidified by solidifying the solidifying agent. The piles 1 and 1 are joined together.

In addition, there are Patent Document 3, Patent Document 4, and the like, and various joining structures have been proposed.

JP-A-2011-52396 Japanese Patent Application Laid-Open No. 4-333717 JP 2006-207117 Japanese Patent Application Laid-Open No. 5-1416

The steel pipe joining structures of Patent Documents 1 to 4 do not require on-site welding work, but they require complicated joining work at the construction site or have a complicated structure, and are not necessarily the whole. However, it cannot be said that it has a great effect on workability and economy.

The present invention has been made based on the above background, and in the case of a ground reinforcement method in which performance against a bending force or a tensile force (pulling force) acting on a pile-shaped ground reinforcing body at the time of an earthquake is not particularly required, a plurality of steel pipes are used. As a means of joining to form a pile-shaped ground reinforcement, not only welding work at the construction site is not required, but also the joining structure is simple, the joining work is easy, and the workability is extremely good, ensuring the joining quality. It is also easy to provide a steel pipe joining structure suitable for a rotary press-fitting method in which a rotary torque is applied to a steel pipe by an auger to penetrate into the ground.

The invention of claim 1 for solving the above-mentioned problems is a steel pipe joining in a ground reinforcing method in which a plurality of steel pipes are joined to form a pile-shaped ground reinforcing body by penetrating the steel pipes into the ground by a rotary press-fitting method. It ’s a structure,
A vertically long rod-shaped body welded and fixed to the outer surfaces of the upper and lower steel pipes butted to be joined, respectively.
A curved plate having a long hole with a contour to which the upper and lower rods are fitted and having a cross-sectional shape along the outer surface of the pipe,
The upper and lower bolts that penetrate the bolt insertion holes provided in the upper and lower steel pipes at the same positions as the bolt insertion holes provided in the upper and lower parts of the curved plate, respectively.
It is characterized by being provided with a nut that is screwed and fastened to each of the bolts.

2. The second aspect of the present invention is the steel pipe joining structure in the ground reinforcement method of the first aspect.
The rod-shaped body is characterized by being a rod-shaped body having a quadrangular cross section.

3. The third aspect of the present invention is the steel pipe joining structure in the ground reinforcement method according to the first or second aspect.
The rod-shaped body and the curved plate are also provided on the opposite side in the diameter direction of the steel pipe.

A fourth aspect of the present invention is the steel pipe joining structure in the ground reinforcement method according to any one of claims 1 to 3.
A tip member provided with a wing member for excavation propulsion is provided at the tip of a tip steel pipe constituting the tip of the pile-shaped ground reinforcing body.

According to the invention of claim 1, when joining a plurality of steel pipes at a construction site to form a pile-shaped ground reinforcing body, not only the on-site welding work is unnecessary, but also the joining structure is extremely simple and the joining work is performed. As described below, the workability of forming a pile-shaped ground reinforcing body is extremely good.
That is, when joining the upper and lower steel pipes, the upper steel pipe is placed on the lower steel pipe that has already penetrated into the ground by the rotary press-fitting method, and then the curved plate is welded and fixed to the outer surfaces of the upper and lower long holes. Place it on the outer surface of the upper and lower steel pipes so that it fits into the rod-shaped body. Next, the upper and lower bolts are passed through the upper and lower bolt insertion holes of the curved plate and the bolt insertion holes of the upper and lower steel pipes, respectively, and nuts are screwed and tightened at the tips of the respective bolts.
As described above, there are no difficult elements in the work of joining the upper and lower steel pipes at the construction site, it is extremely easy, and no special technique is required.

As described below, the steel pipe joint structure constructed as described above can effectively secure the performance as a steel pipe joint structure for forming a pile-shaped ground reinforcing body in the ground reinforcement method.
Regarding the compressive force acting on the pile-shaped ground reinforcing body, the outer diameter and cross-sectional area of the steel pipe may be set to an appropriate outer diameter and cross-sectional area corresponding to the acting compressive force.
Then, in the welding of the rod-shaped body and the steel pipe, the rod-shaped body is welded and fixed to the steel pipe in advance at the factory. There are no particularly difficult elements in the welding work between the rod-shaped body and the steel pipe performed at the factory.

As described above, the invention of claim 1 does not merely eliminate the need for welding work at the construction site, but also a bending force and a tensile force (pulling force) acting on the pile-shaped ground reinforcing body in the event of an earthquake. It effectively utilizes the characteristics of the ground reinforcement method, which does not require any particular performance, and also effectively utilizes the characteristics of the rotary press-fitting method, which applies rotational torque to the steel pipe with an auger and penetrates into the ground. Compared with the steel pipe joining structure described as the prior art, the joining structure is simple, the joining work at the construction site is easy, and the workability is greatly improved.

According to claim 2, since the rod-shaped body is a rod-shaped body having a rectangular cross section, the work of welding and fixing the rod-shaped body to the outer peripheral surface of the steel pipe is easy, and the welding quality is also easy to be ensured.

According to claim 3, since the rod-shaped body and the curved plate are also provided on the opposite sides in the diameter direction of the steel pipe, the steel pipe joint strength can be easily increased.

According to claim 4, since the wing member for excavation propulsion is provided at the tip of the steel pipe constituting the tip of the pile-shaped ground reinforcement, the auger applies rotational torque to the steel pipe to penetrate into the ground. It is suitable as a configuration for forming a pile-shaped ground reinforcement body with steel pipes by the rotary press-fitting method.

(A) shows an embodiment of the steel pipe joint structure in the ground reinforcement method of the present invention, and (b) is a front view of the vicinity of the steel pipe joint structure (steel pipe joint) in the pile-shaped ground reinforcement body, and (b) is (a). It is a top view of the steel pipe contact structure of. (A) is a front view of a main part showing only the curved plate and the steel pipe side portion from which bolts and nuts have been removed in FIG. 1 (a), and (b) is a plan view of (a). (A) is a front view showing only the rod-shaped body in FIG. 2 (a), and (b) is a plan view of (a). (A) is a front view of the curved plate in the steel pipe joint structure of FIG. 1 (a), and (b) is a plan view of (a). (A) is a front view (front view seen from the back) of the curved plate on the back side in FIG. 1 (b), and (b) is a plan view of (a). It is the figure which looked at the tip member of the pile-shaped ground reinforcement body of FIG. 1 (a) from the lower surface. It is a front view which showed the whole of the pile-shaped ground reinforcement body of an Example.

Hereinafter, a mode for carrying out the steel pipe joining structure in the ground reinforcement method of the present invention will be described with reference to the drawings.

The present invention is a steel pipe joining structure in a ground reinforcing method in which a plurality of steel pipes are joined to form a pile-shaped ground reinforcing body by penetrating the steel pipes into the ground by a rotary press-fitting method. ) And (b) show the steel pipe joining structure 10 of one embodiment. The steel pipe joint structure 10 of the illustrated example is a joint structure (upper steel pipe) 1 between the steel pipe (lower steel pipe) 2 at the tip of the pile-shaped ground reinforcing body 11 and the upper steel pipe (upper steel pipe) 1 joined to the lower steel pipe 2 thereof. Steel pipe joint structure).
The upper and lower steel pipes 1 and 2 are butted against each other to be joined, and are welded and fixed to the outer surfaces of the vertically long rod-shaped bodies 3 and 3, respectively.
A curved plate 4 having contoured elongated holes 4a and 4a into which the upper and lower rod-shaped bodies 3 and 3 are fitted and having a cross-sectional shape along the outer surface of the pipe.
The upper and lower bolts 6 and 6 and the bolts 6 and 6 penetrating the bolt insertion holes 1a and 2a provided in the upper and lower bolt insertion holes 4b and 4b provided in the upper and lower parts of the curved plate 4 and the upper and lower steel pipes 1 and 2, respectively. It is joined by nuts 7 and 7 which are screwed and fastened to.

The components of the steel pipe joint structure 10 are shown in FIGS. 2 to 5.
FIG. 2 (a) is a front view of a main part showing only the curved plate 4 and the steel pipe side portion from which bolts and nuts have been removed in FIG. 1 (a), and FIG. 2 (b) is a plan view of (a).
The sizes of the upper and lower steel pipes 1 and 2 of the embodiment have an outer diameter of 114.3 mm and a plate thickness of t @@ mm.
The dimensions of the rod-shaped body 3 welded and fixed to the upper and lower steel pipes 1 and 2, respectively, are as shown in FIGS. 3 (a) and 3 (b), and have a quadrangular cross section of 18 mm × 18 mm and a length of 100 mm.

FIG. 4 shows the curved plate 4 alone. FIG. 4A is a front view of the curved plate 4, and FIG. 4B is a plan view.
The size of the curved plate 4 is an arc plate having a radius of 57.6 mm and an angle of 120 ° along the outer surface of the steel pipe, and has a plate thickness of 4.5 mm and a vertical length of 600 mm. As the angle range of the arc surface of the curved plate 4, an angle of 90 ° to 120 ° can be considered.
The position, width dimension, and vertical length dimension of the elongated hole 4a provided in the curved plate 4 are sizes in which the rod-shaped body 3 welded and fixed to the steel pipes 1 and 2 fits with a slight margin, and is shown in FIG. That's right.

FIG. 5 shows the curved plate 4'on the back side alone. 5 (a) is a front view of the curved plate 4'seen from the back side of FIG. 1, and (b) is a plan view.
The curved plate 4'is the same as the curved plate 4 on the front side of FIG. 4 except that it does not have the upper and lower elongated holes 4a.

In the pile-shaped ground reinforcing body 11 of the embodiment, the tip member 22 provided with the wing member 21 for excavation propulsion is fixed to the steel pipe (lower steel pipe) 2 at the tip portion.
FIG. 6 is a view of the tip member 22 as viewed from the lower surface.
The tip member 22 has a diameter D ₀ larger than the diameter d of the lower steel pipe 2 on the tip surface (lower end surface) of the lower steel pipe 2, and has a diameter D dented upward in the center when viewed from the lower surface side. The circular end face plate 26 in which the concave portion 25 having the circular contour of ₁ is formed is welded and fixed.
The flange portion 27 projecting outward from the recess 25 in the end face plate 26 has a notch 28 extending from the peripheral edge of the end face plate 26 toward the center, and each other is provided on both sides of the notch 28 in the circumferential direction of the end face plate. Inclined surface portions 31, 32 that are inclined upside down are formed.
A square rod-shaped excavation propulsion auxiliary bar 33 extending from the center side of the recess 25 toward the vicinity of the notch 28 is welded and fixed to the recess 25.
Further, an inclined surface portion reinforcing member 39 for reinforcing the downward inclined surface portion 32 is welded and fixed to the lower surface of the end face plate 26.

FIG. 7 is a diagram showing the entire pile-shaped ground reinforcing body 11 of the embodiment. In the illustrated example, the steel pipe joining structure 10 for joining the steel pipe 2 at the lowermost end having the tip member 22 and the steel pipe 1 above the steel pipe 1 and the steel pipe joining structure 10 for joining the steel pipe 1 on the upper side and the steel pipe 15 on the upper side thereof are joined. With the structure 10A, the steel pipe 15 at the upper end is rotationally driven by the rotary drive unit 40 of the pile driver, and the entire pile-shaped ground reinforcing body 11 is rotationally press-fitted into the ground.
In the case of the illustrated example, since the steel pipe 2 at the lower end is short, the steel pipe 2 at the lowermost end and the steel pipe 1 above it are rotationally press-fitted into the ground by the rotary drive unit 40 in a state of being joined by the steel pipe joining structure 10. Next, the steel pipe 1 on the upper side and the steel pipe 15 on the upper side thereof are further rotationally press-fitted into the ground in a state of being joined by the steel pipe joining structure 10'.

According to the steel pipe joining structure 10 described above, when joining a plurality of steel pipes at a construction site to form a pile-shaped ground reinforcing body 11, not only on-site welding work is not required, but also the joining structure is extremely simple. The joining work is easy, and as described below, the workability of forming the pile-shaped ground reinforcing body 11 is extremely good.
That is, when joining the upper and lower steel pipes 1 and 2, the upper steel pipe 1 is placed on the lower steel pipe 2 that has already penetrated into the ground by the rotary press-fitting method, and then the curved plate 4 is formed by the upper and lower elongated holes 4a. It is applied to the outer surfaces of the upper and lower steel pipes 1 and 2 so as to fit into the rod-shaped body 3 welded and fixed to the outer surfaces of the steel pipes 1 and 2. Next, the upper and lower bolts 6 and 6 are passed through the upper and lower bolt insertion holes 4b and 4b of the curved plate 4, and the bolt insertion holes 1a and 2a of the upper and lower steel pipes 1 and 2, respectively, and a nut is attached to the tip of each bolt 6. Screw 7 and tighten.
As described above, there are no difficult elements in the joining work of the upper and lower steel pipes 1 and 2 at the construction site, it is extremely easy, and no special technique is required.

As described below, the steel pipe joining structure 10 constructed as described above can effectively secure the performance as a steel pipe joining structure for forming the pile-shaped ground reinforcing body 11 in the ground reinforcing method.
Regarding the compressive force acting on the pile-shaped ground reinforcing body 11, the outer diameter and cross-sectional area of the steel pipes 1 and 2 may be set to an appropriate outer diameter and cross-sectional area corresponding to the acting compressive force.
Then, in the welding of the rod-shaped body 3 and the steel pipes 1 and 2, the rod-shaped body 3 is welded and fixed to the steel pipes 1 and 2 in advance at the factory. There are no particularly difficult elements in the welding work between the rod-shaped body 3 and the steel pipes 1 and 2 performed at the factory.

As described above, the present invention does not merely eliminate the need for welding work at the construction site, but also has performance against bending force and tensile force (pulling force) acting on the pile-shaped ground reinforcing body 11 at the time of an earthquake. It effectively utilizes the characteristics of the ground reinforcement method, which is not particularly required, and also effectively utilizes the characteristics of the rotary press-fitting method, which applies rotational torque to the steel pipe with an auger and penetrates into the ground. Compared with each steel pipe joining structure described as a technique, the effect that the joining structure is simple, the joining work at the construction site is easy, and the workability is greatly improved can be obtained.

As described above, the present invention is applied to a ground reinforcement method that does not particularly require performance against a bending force or a tensile force (pulling force) acting on a pile-shaped ground reinforcing body at the time of an earthquake, and is mainly used for construction of wooden buildings. It is expected to be applied in.
The steel pipe diameter is assumed to be in the range of 114.3 mmφ to 165.2 mmφ, and the plate thickness is assumed to be @@ mm to @@ mm (manuscript note: please enter the numerical value).
In the embodiment, the rod-shaped body 3 is not provided on the back surface side of the steel pipes 1 and 2, and therefore the curved plate 4'on the back surface side is not provided with the elongated hole 4a, but may be provided if necessary. ..

1 Steel pipe (upper steel pipe)
1a (upper steel pipe) bolt insertion hole 2 steel pipe (lower steel pipe)
2a (lower steel pipe) bolt insertion hole 3 rod-shaped body 4 curved plate 4a long hole 4b (curved plate) bolt insertion hole 4'(back side) curved plate 6 (upper and lower) bolt,
7 Nut 10 Steel pipe joint structure 11 Pile-shaped ground reinforcement 22 Tip member 26 End face plate 25 Recess 26 End face plate 27 Blossom 28 Notch 31 Upward inclined surface 32 Downward inclined surface 33 Excavation propulsion auxiliary bar 39 Inclined surface reinforcing member 40 Rotational drive (of pile driver)

Claims (4)

It is a steel pipe joining structure in the ground reinforcement method in which the steel pipe is penetrated into the ground by the rotary press-fitting method when a pile-shaped ground reinforcing body is formed by joining a plurality of steel pipes.
A vertically long rod-shaped body welded and fixed to the outer surfaces of the upper and lower steel pipes butted to be joined, respectively.
A curved plate having a long hole with a contour to which the upper and lower rods are fitted and having a cross-sectional shape along the outer surface of the pipe,
The upper and lower bolts that penetrate the bolt insertion holes provided in the upper and lower steel pipes at the same positions as the bolt insertion holes provided in the upper and lower parts of the curved plate, respectively.
A steel pipe joining structure in a ground reinforcement method, characterized in that each bolt is provided with a nut that is screwed and fastened. The steel pipe joining structure according to claim 1, wherein the rod-shaped body is a rod-shaped body having a quadrangular cross section. The steel pipe joining structure according to claim 1 or 2, wherein the rod-shaped body and the curved plate are also provided on the opposite sides of the steel pipe in the diameter direction. One of claims 1 to 3, wherein an end face plate provided with a wing member for excavation propulsion is provided at the tip of a tip steel pipe constituting the tip of the pile-shaped ground reinforcing body. Steel pipe joint structure in the ground reinforcement method described in.

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